RE: [stella] Math riddle : Loading TIM64T with 43 burns only 36 scanlines (not 37)

Subject: RE: [stella] Math riddle : Loading TIM64T with 43 burns only 36 scanlines (not 37)
From: "Dennis Debro" <ddebro@xxxxxxxxxxxxx>
Date: Mon, 10 May 2004 22:12:59 -0400
Hi there,

> Of course in the 2600, there are no interrupts.  So you have to check when
> the count is 255.

You can use the interrupt to determine when the timer is done. It's done in
some games. One in particular is Moonsweeper (since I'm transcribing it
now). IIRC Bob also does this in Dragonfire.

Bob sets the timer and then does...

VBOUT    BIT     TIMOUT                  ; WAIT FOR VB OVER
         BPL     VBOUT

to determine when the timer is done. TIMOUT is register $285.

Take care,
Dennis 


----------------------------------------------------------------------------------------------
Archives (includes files) at http://www.biglist.com/lists/stella/archives/
Unsub & more at http://www.biglist.com/lists/stella/


Current Thread